docstr: Prefetch the data required for this epoch.
docstr_tok: ["Prefetch","the","data","required","for","this","epoch","."]
code: def prefetch(self, indices):
      """Prefetch the data required for this epoch."""
      for ds in self.defn.values():
          if getattr(ds, "supports_prefetch", False):
              ds.prefetch(indices)
  
file_path: fairseq/fairseq/data/nested_dictionary_dataset.py
imports: from collections import OrderedDict
  import torch
  from torch.utils.data.dataloader import default_collate
  from .None import FairseqDataset
label_desc: Use image node_id 8 for calling the NestedDictionaryDataset obj's underlying member method code with example usage: obj.prefetch(indices) without return types